Bighorn Skull (IMAGE) PLOS Caption This is a bighorn sheep (Ovis canadensis) skull on Tiburón Island. Skull from bighorn sheep population introduced on Tiburón Island, Gulf of California, in 1975. Radiocarbon dating and ancient DNA analysis from a local cave now show that this introduction unintentionally re-established bighorn sheep that had gone extinct on the island. Credit Photo by B.T. Wilder Usage Restrictions Photo by B.T. Wilder License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.